Barnum House, Neoclassical house museum in Grafton, Ontario, Canada

Barnum House is a Neoclassical residence built between 1817 and 1819 just outside Grafton, Ontario. Its facade has a central temple front with flanking wings, pilasters linked by elliptical arches, and finely scaled classical detailing. The same ornament reappears in the woodwork of several rooms, notably the parlour. A two-storey gallery and resource centre addition dates from the 1989–1991 restoration.

Eliakim Barnum bought the property from his brother-in-law James Norris, whose earlier house on the site had burned during the War of 1812 while British soldiers were billeted there. Barnum, a United Empire Loyalist from Vermont who arrived in Haldimand Township in 1807, built the present house between 1817 and 1819. It was designated a National Historic Site of Canada in 1959.

Eliakim Barnum named the house for his family and helped found St. George's Anglican Church and the township's first school. The interior woodwork, especially in the parlour, repeats the exterior's Neoclassical motifs. The collection holds Georgian and Victorian furniture, china, books, cookware, toys and photographs.

The site closed for several years from September 2003 and opened for only three months in summer 2007 after a private donation; check current opening before travelling. The two-storey gallery and resource centre added in the 1989–1991 restoration stands beside the original house. The house sits just outside Grafton in Alnwick/Haldimand Township.

The collection holds a Clementi piano from the early 19th century, believed to be the only surviving instrument of its kind. Barnum House opened as Ontario's first house museum in 1940, after the Architectural Conservancy of Ontario restored it to its original state.